Bug 645416, part 8 - Support passing symbols across compartment boundaries. r=terrence.

Trivial. Since symbols are always allocated in the atoms compartment and all
compartments are allowed to have direct references to them, Compartment::wrap
on a symbol is a no-op.

--HG--
extra : rebase_source : 2f51ff0b3870885de8c6ef6a82efa7398e17d5e8

js/src/jit-test/tests/basic/symbol-in-loop.js

@@ -0,0 +1,8 @@
+function f() {
+    return Object(Symbol());
+}
+
+for (var i = 0; i < 4; i++) {
+    f();
+    gc();
+}

js/src/jit-test/tests/debug/Frame-arguments-01.js

@@ -22,8 +22,10 @@ g.eval("function f() { debugger; }");
 hits = 0;
 g.eval("args = []; f();");
 g.eval("this.f();");
-g.eval("args = ['hello', 3.14, true, false, null, undefined]; f.apply(undefined, args);");
-g.eval("f('hello', 3.14, true, false, null, undefined);");
+g.eval("var world = Symbol('world'); " +
+       "args = ['hello', world, 3.14, true, false, null, undefined]; " +
+       "f('hello', world, 3.14, true, false, null, undefined);");
+g.eval("f.apply(undefined, args);");
 g.eval("args = [-0, NaN, -1/0]; this.f(-0, NaN, -1/0);");
 assertEq(hits, 5);
 

js/src/jit-test/tests/debug/Frame-evalWithBindings-03.js

@@ -5,12 +5,12 @@ var global = dbg.addDebuggee(g);
 var hits = 0;
 dbg.onDebuggerStatement = function (frame) {
     var argc = frame.arguments.length;
-    assertEq(argc, 7);
+    assertEq(argc, 8);
     assertEq(frame.evalWithBindings("arguments[prop]", {prop: "length"}).return, argc);
     for (var i = 0; i < argc; i++)
         assertEq(frame.evalWithBindings("arguments[i]", {i: i}).return, frame.arguments[i]);
     hits++;
 };
 g.eval("function f() { debugger; }");
-g.eval("f(undefined, -0, NaN, '\uffff', Array.prototype, Math, f);");
+g.eval("f(undefined, -0, NaN, '\uffff', Symbol('alpha'), Array.prototype, Math, f);");
 assertEq(hits, 1);

js/src/jit-test/tests/debug/Frame-onPop-17.js

@@ -23,6 +23,7 @@ test(null);
 test(false);
 test(1);
 test("stringy");
+test(Symbol("symbolic"));
 test({});
 test([]);
 

js/src/jit-test/tests/debug/Frame-this-01.js

@@ -16,7 +16,9 @@ g.eval("Number.prototype.f = f; v = 3.14; v.f();");
 g.eval("f.call(v);");
 g.eval("String.prototype.f = f; v = 'hello'; v.f();");
 g.eval("f.call(v);");
+g.eval("Symbol.prototype.f = f; v = Symbol('world'); v.f();");
+g.eval("f.call(v);");
 g.eval("v = undefined; f.call(v);");
 g.eval("v = null; f.call(v);");
 
-assertEq(hits, 8);
+assertEq(hits, 10);

js/src/jit-test/tests/debug/Frame-this-03.js

@@ -21,7 +21,9 @@ g.eval("Number.prototype.f = f; v = 3.14; v.f();");
 g.eval("f.call(v);");
 g.eval("String.prototype.f = f; v = 'hello'; v.f();");
 g.eval("f.call(v);");
+g.eval("Symbol.prototype.f = f; v = Symbol('world'); v.f();");
+g.eval("f.call(v);");
 g.eval("v = undefined; f.call(v);");
 g.eval("v = null; f.call(v);");
 
-assertEq(hits, 8);
+assertEq(hits, 10);

js/src/jit-test/tests/debug/Object-makeDebuggeeValue-01.js

@@ -38,3 +38,5 @@ assertEq(gw.makeDebuggeeValue(null), null);
 assertEq(gw.makeDebuggeeValue(1729), 1729);
 assertEq(gw.makeDebuggeeValue(Math.PI), Math.PI);
 assertEq(gw.makeDebuggeeValue(undefined), undefined);
+var s = g.eval("Symbol('Stavromula Beta')");
+assertEq(gw.makeDebuggeeValue(s), s);

js/src/jscompartmentinlines.h

@@ -56,6 +56,13 @@ JSCompartment::wrap(JSContext *cx, JS::MutableHandleValue vp, JS::HandleObject e
     if (!vp.isMarkable())
         return true;
 
+    /*
+     * Symbols are GC things, but never need to be wrapped or copied because
+     * they are always allocated in the atoms compartment.
+     */
+    if (vp.isSymbol())
+        return true;
+
     /* Handle strings. */
     if (vp.isString()) {
         JS::RootedString str(cx, vp.toString());

js/src/tests/ecma_6/Symbol/realms.js

@@ -0,0 +1,26 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/ */
+
+// Symbols can be shared across realms.
+
+if (typeof Reflect !== "undefined" && typeof Reflect.Realm === "function") {
+    throw new Error("Congratulations on implementing Reflect.Realm! " +
+                    "Please update this test to use it.");
+}
+if (typeof newGlobal === "function") {
+    var g = newGlobal();
+    var gj = g.eval("jones = Symbol('jones')");
+    assertEq(typeof gj, "symbol");
+    assertEq(g.jones, g.jones);
+    assertEq(gj, g.jones);
+    assertEq(gj !== Symbol("jones"), true);
+
+    // A symbol can be round-tripped to another realm and back;
+    // the result is the original symbol.
+    var smith = Symbol("smith");
+    g.smith = smith;  // put smith into the realm
+    assertEq(g.smith, smith);  // pull it back out
+}
+
+if (typeof reportCompare === "function")
+    reportCompare(0, 0);